(1) Field of the Invention
The present invention relates to an apparatus for supplying raw materials at constant amounts having a raw material tank for storing and feeding raw materials, a belt for transferring raw materials, a level control guide for defining a thickness of raw materials on the belt, and a belt cover, which can supply at constant amounts wet raw materials used when ceramic honeycombs are extruded.
(2) Prior Art Statement
FIG. 2 is a schematic view showing one embodiment of a known apparatus for supplying raw materials at constant amounts, which can supply at constant amounts wet raw materials used when ceramic honeycombs are extruded. In the embodiment shown in FIG. 2, the apparatus for supplying raw materials at constant amounts 51 comprises a belt 54, belt drive rollers 56 connected to a motor (not shown), a belt cover 52 for covering a roller 57 for measuring a weight of the raw materials on the belt 54 (weight measuring device is not shown) and so on, and a raw material tank 53 for feeding the raw materials arranged through the belt cover 52. The belt 54 functions to transfer the raw materials from the raw material tank 53 to a forming apparatus (not shown). Moreover, a numeral 55 is a level control guide provided to an under portion of the raw material tank 53. A level of the raw materials on the belt 54 can be controlled by varying a position of a tip portion of the level control guide 55 with respect to the belt 54. The level control guide 55 is preliminarily fixed by a bolt and so on to have a predetermined height prior to an apparatus operation start.
In the known apparatus for supplying raw materials at constant amounts 51 having the construction mentioned above, after the level control guide 55 is set, the raw materials such as for example ceramic powders are supplied from the raw material tank 53 on the belt 54 moved in a forward direction. On the belt 54, the supplied raw materials are defined to have a constant width. Therefore, a constant amount of the raw materials can be transferred by setting the level control guide 55. Then, the raw materials are transferred to a raw material supply path 58 for the forming apparatus, which is arranged at a forward side of the belt cover 52. In this manner, the raw material supplying at constant amounts is performed.
In the known apparatus for supplying raw materials at constant amounts 51 having the construction mentioned above, since the belt 54 is moved only in a forward direction, the raw materials to be removed due to a raw material change or a maintenance are once discharged to a forming apparatus side through the raw material supply path 58, and then new raw materials are supplied or a maintenance is performed. In this case, if the raw materials to be removed are supplied to the forming apparatus, it is not possible to perform the raw material supplying at constant amounts. Therefore, in the case of varying the raw materials or in the case of performing the maintenance, the raw materials to be removed are discharged through another path to an outside or the forming apparatus is once detached from the apparatus for supplying at constant amounts.
Moreover, if clods of the raw materials are generated, the clods get stuck on the level control guide 55 and a thickness of the raw materials becomes partly thin, so that it is not possible to perform the raw material supplying at constant amounts. Therefore, it is necessary to make a height of the level control guide 55 higher so as to pass the clods through the level control guide 55. In this case, there is a drawback such that a part of the belt cover 52 is detached. Further, the level control guide 55 is fixed after height adjustment prior to the raw material supplying. Therefore, there occurs a case such that the raw materials are not supplied at constant amounts if a supplying amount of the raw material is varied during operations. In this case, it is also necessary to adjust a height of the level control guide 55 again after the operations are stopped. Moreover, there is a drawback such that a thickness of the raw materials on the belt 54 is varied and thus becomes uneven. Further, there is a drawback such that, since the belt cover 52 is made of non-transparent plate, a raw material state on the belt is not observed, so that a stableness of supplying the raw materials at constant amounts with respect to the clods is not checked.
An object of the invention is to eliminate the drawback mentioned above and to provide an apparatus for supplying raw materials at constant amounts which can remove the raw materials easily without supplying the raw materials to a forming apparatus, vary a thickness of the raw materials during operations, perform a visual observation of a raw material supplying state and make even a thickness of the raw materials on the belt, even if the raw materials to be removed due to a raw material change or a maintenance are discharged.
According to the invention, an apparatus for supplying raw materials at constant amounts having a raw material tank for storing and feeding raw materials, a belt for transferring raw materials, a level control guide for defining a thickness of raw materials on the belt, and a belt cover, comprises: a reversible belt drive motor for controlling a rotation direction of the belt forward and backward; and a device for removing raw materials arranged at a backward side of the belt; wherein, in the case of supplying the raw materials at constant amounts, a normal operation of supplying the raw materials is performed by rotating the belt in a forward direction, and, in the case of removing the raw materials arranged on the belt and in the raw material tank, the raw materials are transferred to the device for removing raw materials arranged at a backward side of the belt by rotating the belt in a backward direction so as to remove the raw materials from the belt and the raw material tank.
In the present invention, since use is made of a reversible belt drive motor for controlling a rotation direction of the belt forward and backward and a device for removing raw materials arranged at a backward side of the belt, in the case of a raw material change or a maintenance, a belt rotation direction can be reversed and the raw materials to be removed remaining on the belt is supplied to the device for removing raw materials. Therefore, it is possible to remove the raw materials easily without supplying the raw materials to a forming apparatus.
As one preferred embodiment, a door member, which can be opened and closed, is arranged to a part of an under portion of the raw material tank. In this embodiment, during the raw material removing operation, clods do not get stuck on the under portion of the raw material tank if the door member is opened. Therefore, it is possible to perform the raw material removing operation more easily. Moreover, as the another preferred embodiment, inside raw material supplying states are directly observed from the outside by making a part of or an overall part of the belt cover transparent. In this embodiment, it is possible to observe the raw material supplying states on the belt more effectively. Further, as the further another preferred embodiment, an operation portion of the level control guide is arranged outside of the belt cover so as to operate the level control guide from the outside, and a level of the raw materials on the belt is controlled from the outside. In this embodiment, it is possible to control the raw material level from the outside easily. In addition, if a tip portion of the level control guide is inclined at a predetermined angle, it is possible to reduce an unevenness of the raw materials on the belt, and it is possible to perform a smooth raw material supplying operation.